This application is for funds to conduct an investigation of the distribution, chemistry, biosynthesis, and intermediary metabolism of lenticular sphingolipids. Studies will be done on the distribution of ceramides in different regions of the human normal and cataractous lenses. Details will be sought about the mechanism of ceramide accumulation in human cataracts. These investigations will include studies on the biosynthesis of ceramide in vitro, using sphingosine bases and labeled acyl-CoA. Biodegradation of ceramide will be studied by using chemically synthesized radioactive ceramide as substrate.